Lining up in front of members of the 130-strong team on the banks of the River Thames in London, Harry, 29, said, "I cannot wait to watch this team competing against the other nations" in four weeks.

More than 400 competitors from 14 nations (including the USA) will take part in the Games for wounded warriors in London from Sept. 10-14.

"I'd like to congratulate you on making the team," the casually dressed prince told them. "These men and women here have achieved so much already but being selected for this team is another significant milestone in their life beyond injury."

Harry said the Games were not just for those taking part, but also for "all those in the wider family," including those who didn't make the team and the people at home who support them.

And with Harry being Harry, there were also some laughs.

To chuckles, he opened his address with, "So … prosthetics, dogs, wheelchairs, high-performance cars, 4x4s, tattoos … we've got everything here – it could only be the Invictus Games."

Then, as a gust of wind blew his papers away, causing him to leap in order to catch them as they fluttered along the small stage, he quipped, "No blowing from the left, thank you!"

Harry also got to meet the team's mascot, Fire, a 5½-year-old black Labrador, who was injured by an Improvised Explosive Device in Afghanistan in January 2012 while doing her job of sniffing out bombs for one of the royal army veterinary corps.

Col. Neil Smith, 48, who now looks after Fire, said, "She broke her jaw, pellets from the bomb went through her wrist and she lost a lot of skin and muscle."

He continued: "But she's made a remarkable recovery, although we've retired her now from operational service."

After the speeches, Harry moved through the team, joining them for group selfies and chatting about their training and backgrounds.

Clive Smith, 28, who was medically discharged from the army after losing both legs below the knees after an IED explosion, is taking part in a hand cycling event.

"Harry has done a lot behind the scenes," he told PEOPLE. "The idea wouldn't have been viable if Harry wasn't involved."

Multiple Sclerosis sufferer Grant Harvey, 41, who is taking part in the wheelchair rugby event, told PEOPLE, "He has an honest interest with the wounded, injured and sick in the armed forces. He likes to see that they get treated for the conditions they have and [that] everything out there that can be given to us is available."

Harry, who wrote a moving personal editorial about his inspiration for the games and the "horrendous" injuries he witnessed on two tours of Afghanistan, also thanked the media for "showing a huge amount of support for what we are trying to achieve here. I appreciate it. It does make a difference."